Patent US4508887A successfully refreshed from Google Patents.
US4508887A
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Method and novel catalyst compositions for preparing polyorganosiloxanes
Assignee: Dow Silicones Corp
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Filing: 1983-08-01
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Granted: 1985-04-02
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Expires: 2003-08-01
Abstract
Abstract Polyorganosiloxanes are prepared from at least one organosiloxane reactant containing an average of more than one silicon-bonded hydroxyl group per molecule using novel catalyst compositions consisting essentially of (1) at least one salt formed from equimolar amounts of an amine and sulfuric acid, phosphoric acid, a carboxylic acid or an organosulfonic acid and (2) an unreacted acid selected from the group consisting of sulfuric acid and fluorinated alkanesulfonic acids.
Inventors
- 👤 Charles F. Kohl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:35
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/42; C08G77/44; C08G77/04; C08G77/06; C08G77/08; C08K; C08K5/00
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
204 words
A method for preparing a polyorganosiloxane, said method comprising the steps of (I) forming a liquid reaction mixture comprising (A) at least one hydroxyl-containing organosiloxane reactant containing repeating units of the formula R a 1 SiO.sub.(4-a)/2 where each R 1 is individually selected from the group consisting of monovalent inertly substituted and monovalent unsubstituted hydrocarbon radicals containing from 1 to 6 carbon atoms and a has an average value of from 1 to 2; (B) a catalytically effective amount of a catalyst composition consisting essentially of (1) at least one salt derived from substantially equivalent amounts of an organic amine containing at least one primary, secondary or tertiary nitrogen atom and an acid selected from the group consisting of mono- and polyfunctional carboxylic acids, mono- and polyfunctional organosulfonic acids, phosphoric acid and sulfonic acid; and (2) at least one unreacted acid selected from the group consisting of fluorinated alkanesulfonic acids and sulfuric acid; and (C) an inert liquid reaction medium; (II) heating said reaction mixture at a temperature of from 30° C. to the boiling point of the reaction mixture while removing the by-product water from the reaction mixture; and (III) maintaining said temperature for a period of time sufficient to form said polyorganosiloxane.
Claim 2
Independent Claim
204 words
A method for preparing a polyorganosiloxane, said method comprising the steps of (I) forming a liquid reaction mixture comprising (A) at least one hydroxyl-containing organosiloxane reactant containing repeating units of the formula R a 1 SiO.sub.(4-a)/2 where each R 1 is individually selected from the group consisting of monovalent inertly substituted and monovalent unsubstituted hydrocarbon radicals containing from 1 to 6 carbon atoms and a has an average value of from 1 to 2; (B) a catalytically effective amount of a catalyst composition consisting essentially of (1) at least one salt derived from substantially equivalent amounts of an organic amine containing at least one primary, secondary or tertiary nitrogen atom and an acid selected from the group consisting of mono- and polyfunctional carboxylic acids, mono- and polyfunctional organosulfonic acids, phosphoric acid and sulfonic acid; and (2) at least one unreacted acid selected from the group consisting of fluorinated alkanesulfonic acids and sulfuric acid; and (C) an inert liquid reaction medium; (II) heating said reaction mixture at a temperature of from 30° C. to the boiling point of the reaction mixture while removing the by-product water from the reaction mixture; and (III) maintaining said temperature for a period of time sufficient to form said polyorganosiloxane.
Claim 3
Dependent Claim
22 words
A method according to claim 1 where R a 1 SiO.sub.(4-a)/2 represents a dimethylsiloxane unit, a methylphenylsiloxane unit or a methyl-3,3,3-trifluoropropylsiloxane unit.
Claim 4
Dependent Claim
189 words
A method according to claim 1 where said polyorganosiloxane is a block copolymer and said reaction mixture includes (i) at least one organosiloxane reactant selected from the group consisting of hydroxyl-terminated polydiorganosiloxanes containing repeating units of the formula R 2 R 3 SiO, where R 2 and R 3 are identical or different and represent unsubstituted or inertly substituted monovalent hydrocarbon radicals containing from 1 to 6 carbon atoms, and (ii) at least one organosiloxane reactant containing repeating units of the formula ##EQU4## where R 4 is a hydrocarbon radical selected from the same group as R 2 and R 3 , with the proviso that R 2 , R 3 and R 4 are not identical when b is 2; R 5 is alkyl containing from 1 to 4 carbon atoms; b has an average value of from 1 to 2, inclusive; c is at least 0.01; d has an average value of from 0 to 1.5, the sum of b, c and d does not exceed 3; and the molar ratio of R 2 R 3 SiO units to ##EQU5## units is from 0.1:1 to 10:1, respectively.
Claim 5
Dependent Claim
26 words
A method according to claim 3 where said polydiorganosiloxane (i) is a polydimethylsiloxane and contains an average of from 10 to 100 repeating units per molecule.
Claim 6
Dependent Claim
11 words
A method according to claim 3 where R 4 is phenyl.
Claim 7
Dependent Claim
11 words
A method according to claim 3 where R 5 is methyl.
Claim 8
Dependent Claim
29 words
A method according to claim 3 where the molar ratio of repeating units in polydiorganosiloxane (i) to repeating units in organosiloxane reactant (ii) is from 0.7:1 to 3.5:1, respectively.
Claim 9
Dependent Claim
17 words
A method according to claim 3 where said organosiloxane reactant (ii) is a hydrolysis product of phenyltrimethoxysilane.
Claim 10
Dependent Claim
26 words
A method according to claim 3 where b is from 1 to 1.3, c is from 0.1 to 1 and d is from 0 to 0.6.
Claim 11
Dependent Claim
34 words
A method according to claim 1 where said salt (B) is derived from a monoalkylamine or a 1,1,3,3-tetraalkylguanidine wherein the alkyl radicals of the monoalkylamine and tetraalkylguanidine contain from 1 to 8 carbon atoms.
Claim 12
Dependent Claim
16 words
A method according to claim 10 where the monoalkylamine is t-butylamine and the 1,1,3,3-tetraalkylguanidine is 1,1,3,3-tetramethylguanidine.
Claim 13
Dependent Claim
24 words
A method according to claim 1 where said salt (B) is derived from sulfuric acid, a polyfluorinated carboxylic acid or a polyfluorinated alkanesulfonic acid.
Claim 14
Dependent Claim
25 words
A method according to claim 12 where said polyfluorinated carboxylic acid is trifluoroacetic acid and the polyfluorinated alkanesulfonic acid is trifluoromethanesulfonic acid or tetrafluoroethanesulfonic acid.
Claim 15
Dependent Claim
13 words
A method according to claim 1 where said unreacted acid is sulfuric acid.
Claim 16
Dependent Claim
64 words
A method according to claim 1 where said unreacted acid is a fluorinated alkanesulfonic acid represented by the formula R f SO 3 H where R f represents a perfluoroalkyl radical containing from 1 to 12 carbon atoms, a H(CF 2 ) d CF 2 -- radical or a F(CF 2 ) d CFHCF 2 -- radical and d is 0, 1, or 2.
Claim 17
Dependent Claim
17 words
A method according to claim 15 where said fluorinated alkanesulfonic acid is trifluoromethanesulfonic acid or tetrafluoroethanesulfonic acid.
Claim 18
Dependent Claim
37 words
A method according to claim 1 where said salt (I) is present at a concentration of from 10 to 500 parts by weight per million parts by weight of total organosiloxane reactants present in said reaction mixture.
Claim 19
Dependent Claim
52 words
A method according to claim 1 where the salt component of said catalyst composition is a trifluoroacetate or trifluoromethanesulfonate of a lower N-alkyl amine and is present at a concentration of from 50 to 200 parts by weight per million parts by weight of total organosiloxane reactants present in said reaction mixture.
Claim 20
Dependent Claim
43 words
A method according to claim 1 wherein the unreacted acid component (2) of said catalyst composition is present at a concentration of from 10 to 300 parts by weight per million parts by weight of total organosiloxane reactants present in said reaction mixture.
Claim 21
Dependent Claim
23 words
A method according to claim 1 where the weight ratio of salt (1) to unreacted acid (2) is from 1:30 to 50:1, respectively.
Claim 22
Dependent Claim
20 words
A method according to claim 19 where the weight ratio of (1) to (2) is from 1:3 to 3:1, respectively.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-04-01 | 1988-10-01 | 1989-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-01 | 1992-10-01 | 1993-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-01 | 1996-10-01 | 1997-04-02 | $7700.00 | Window Closed / Lapsed |